Stress and the butterfly effect

By Jon Teel '12

For beetles in the Sierra Nevada and butterflies in Finland alike, when it comes to climate, there’s a shared message: A change is gonna come. To survive, these insects will have to either adapt, move to a more favorable locale, or face extinction. Unraveling how this happens is the source of a Fulbright Fellowship for Professor of Biology Elizabeth Dahlhoff this fall.

Dahlhoff has spent much of the past 15 years studying willow beetles in the Sierra Nevada mountains in California. About five years after she and fellow biologist Nathan Rank reported that a particular gene appeared to be under natural selection in response to environmental change in these beetles, she discovered that a research group in Finland studying a butterfly known as the Glanville fritillary was citing their work. The reason: Though separated by 5,000 miles, Finnish butterfly populations also showed changes in this same gene.

The gene in question codes for an enzyme critical for energy metabolism during activities such as eating and mating. And changes in gene frequency were directly related to shifts in environmental temperature. One special insight the butterflies offer: Finnish researchers know exactly when the evolutionary changes in this gene started taking place.

“Butterflies colonized the Aland Island, off the southwest coast of Finland, in the 1970s, but are now extinct on the mainland due to habitat loss,” Dahlhoff says. Because of the isolated location, scientists can tell when the butterflies began to adapt to unique climate conditions there.

For the 2011–12 academic year, Dahlhoff will join the Metapopulation Research Group at the University of Helsinki, collaborating on research that should benefit biologists—and butterflies and beetles—on both sides of the pond.